My Science Box

Assessment

1. Have students answer summary questions about the extraction.

• Why is it necessary to mash the strawberries?
• What is the purpose of the detergent?
• What is the purpose of the salt?
• Name a liquid that DNA is not soluble in.
• Is the DNA that you extracted pure? What else might be attached to the DNA?
• Why might some people get more DNA than others?
• Can you see a single strand of DNA without a microscope? Explain how you were able to see the DNA in this experiment without magnification.

Going Further

1. Make models of DNA (see DNA Models lesson).
2. Try to isolate DNA from other soft fruits and vegetables. This may even be done as homework. Compare the DNA yields and discuss why different plants would give different results.